1. Field of the Invention
The present invention relates to a magnetic head, and more particularly, to a perpendicular magnetic recording head which is capable of effectively preventing a short circuit from occurring between coil layers of a recording head and obtaining an excellent coil peculiarity and a method of manufacturing the same.
2. Description of the Related Art
Each of FIG. 21 of JP-A-2002-170205 (Pub. No.: US 2002/0089783 A1) and FIG. 1 of JP-A-05-242429 discloses a configuration of a coil layer wound in a solenoid shape around a magnetic pole layer or a core layer which forms an inductive head (recording head).
In order to effectively use a three-dimensional space around the core layer, the coil layer is preferably wound in a helical shape. Therefore, it is possible to achieve a small-sized inductive head with superior magnetization efficiency.
In each of JP-A-2002-170205 and JP-A-05-242429, a front view where peripheral portions of a lower coil layer formed below a magnetic pole layer (core layer) and an upper coil layer formed above the magnetic pole layer are viewed from a recording medium facing surface side is not shown, but, it can be assumed from the described contents that a front view of a thin film magnetic head shown in FIG. 21 of JP-A-2002-170205 corresponds approximately to FIG. 17 and a front view of a thin film magnetic head shown in FIG. 1 of JP-A-05-242429 corresponds approximately to FIG. 18.
That is, in a thin film magnetic head H10 disclosed in FIG. 21 of JP-A-2002-170205, a lower coil layer 118 and an upper coil layer 123 are electrically connected to each other through a connecting layer 150, as shown in FIG. 17. In a thin film magnetic head H20 shown in FIG. 1 of JP-A-05-242429, a connecting portion 223c formed in an upper coil layer 223 is electrically connected to a lower coil layer 218, as shown in FIG. 18. In addition, the connecting layer 150 or the connecting portion 223c is formed in a direction which extends in a perpendicular direction with respect to a vertical direction of the thin film magnetic head (a direction of Z1-Z2 in the drawing).
According to a method of manufacturing the thin film magnetic head H10 shown in FIG. 21 of JP-A-2002-170205 and a method of manufacturing the thin film magnetic head H20 shown in FIG. 1 of JP-A-05-242429, by means of an etching technology, connection holes 160a and 260a (through holes) are formed in insulating layers 119 and 219 that cover lower coil layers 118 and 218 formed below magnetic pole layers 120 and 220 (core layers) and insulating layers 160 and 260 formed over a region ranging from the top surfaces of the magnetic pole layers 120 and 220 (core layers) to both sides of the magnetic pole layers 120 and 220 (core layers) in a track width direction, and top surfaces of the lower coil layers 118 and 218 are exposed.
In addition, in the thin film magnetic head shown in FIG. 21 of JP-A-2002-170205, after the connecting layer 150 shown in FIG. 17 is formed in the connection hole 160a, an upper coil layer 123 is formed such that the top surface of the connecting layer and the bottom surface of the upper coil layer 123 are electrically connected to each other. In this case, the lower coil layer 118 and the upper coil layer 123 are electrically connected to each other through the connecting layer 150 so as to form a coil layer wound in a toroidal shape around the magnetic layer 120.
In addition, in the perpendicular magnetic head H20 shown in FIG. 1 of JP-A-05-242429, the upper coil layer 223 is formed such that the connecting portion 223c of the upper coil layer 223 shown in FIG. 18 is formed in the through hole 260a. As a result, the lower coil layer 218 and the upper coil layer 223 are electrically connected to each other so as to form a coil layer wound in a helical shape around the core layer 220.
However, in the thin film magnetic head H10 disclosed in FIG. 21 of JP-A-2002-170205, the lower coil layer 218 and the upper coil layer 223 are connected to each other through the connecting layer 150. However, as shown in FIG. 17, when viewed from the facing surface of the recording medium, the lower coil layer 118 and the upper coil layer 123 extend linearly toward the track width direction (a direction of X1-X2 in the drawing). As a result, a length between the lower coil layer 118 and the upper coil layer 123 in the vertical direction (a direction of Z1-Z2 in the drawing) is large. Therefore, since the length of the connecting layer 150 for connecting the lower coil layer 118 to the upper coil layer 123 in the vertical direction is also increased, a resistance value of the entire coil layer may be increased.
In the meantime, in the thin film magnetic head H20 disclosed in FIG. 1 of JP-A-05-242429, since the connecting portion 223c of the upper coil layer 223 is formed so as to extend toward the lower coil layer 218, the lower coil layer 218 and the upper coil layer 223 can be electrically connected to each other without the connecting layer 150 interposed therebetween, as in the thin film magnetic head disclosed in FIG. 1 of JP-A-2002-170205 (the thin film magnetic head H10 shown in FIG. 17). Therefore, a resistance value of the entire coil layer can be decreased.
In the meantime, in the thin film magnetic head H20 disclosed in FIG. 1 of JP-A-05-242429, as shown in FIG. 18, the upper coil layer 223 is vertically bent at a part of the connecting portion 223c in a downward direction (a direction of Z2 in the drawing) toward the lower coil layer 218. For this reason, when the upper coil layer 223 is formed on the insulating layer 260 shown in FIG. 18, the abnormal shape may be easily formed and a short circuit may easily occur between the upper coil layers 223. As a result, it is not possible to obtain a superior coil peculiarity.
Specifically, when forming the upper coil layer 223 of the thin film magnetic head H20 shown in FIG. 1 of JP-A-05-242429, as shown in FIG. 18, a resist layer is coated on an insulating layer 260 and a through hole 260a where the side surfaces 260b are formed in a direction vertical to a film surface (a direction of Z1-Z2 in the drawing), as corner portions 260c of the insulating layer 260 are formed at a right angle, and a resist pattern is formed by exposing and developing the pattern of the upper coil layer 223 in the resist layer. And then, the upper coil layer 223 is formed by means of a known method, such as a plating method or the like, using the resist pattern. However, since the side surfaces 260b of the through hole 260a is formed in a direction vertical to the film surface, when the resist layer is exposed, a resist pattern falls into disarray in the vicinity of the side surfaces 260b of the through hole 260a due to the diffused reflection of the light occurring on the side surfaces 260b. For this reason, the abnormal shape may occur in the upper coil layer 223 formed on the basis of the resist pattern, and a short circuit or the like may occur in the upper coil layer 223.